An elevator comprises typically a car, an elevator shaft, a machine room, lifting machinery, ropes, and a counter weight. The elevator car may be positioned within a car frame, whereby the car frame may be integrated into the car structures or formed as a separate frame. The lifting machinery may be positioned in the machine room and may comprise a drive, an electric motor, a drive pulley, and a machinery brake. The lifting machinery may move the car in a vertical direction upwards and downwards in the vertically extending elevator shaft. The ropes may connect the car frame via the drive pulley to the counter weight. The car frame may further be supported with glide means on car guide rails extending along the height of the shaft. The car guide rails may be supported with fastening brackets on the side wall structures of the shaft. The glide means may engage with the car guide rails and keep the car in position in the horizontal plane when the car moves upwards and downwards in the elevator shaft. The counter weight may be supported in a corresponding way on counter weight guide rails supported on the wall structure of the shaft. The car may transport people and/or goods between the landings in the building. The shaft may be formed so that the wall structure is formed of solid walls or so that the wall structure is formed of an open steel structure.
The guide rails may be formed of guide rail elements of a certain length. The guide rail elements may be connected in the installation phase end-on-end one after the other in the elevator shaft. There may be adjustable fastening means between the guide rails and the brackets in order to facilitate adjustment of the guide rails. When aligning elevator guide rails the adjustable fastening means in connection with each bracket needs to be adjusted based on the straightness measurement of the guide rail.
One or several plumb lines may be arranged in the vicinity of the guide rails. The plumb lines run vertically in the shaft and are fixed at the top and at the bottom of the shaft. The plumb lines form a reference line for the straightness of the guide rails.